Hitherto, a hybrid vehicle including a transmission mechanism is known. For example, Patent Literature 1 discloses a technique of a driving device for a hybrid vehicle including a transmission mechanism which transmits a rotation of an internal-combustion engine to a power distribution mechanism while changing the rotation thereof, a first transmission shaft which transmits power from the internal-combustion engine to the transmission mechanism, and a second transmission shaft which transmits power output from the transmission mechanism to the power distribution mechanism.